"The ROC is focused on looking after the interests of members and ensuring their money is spent within a way that is properly authorised and complies with rules of the organisation and complies with the Act," the commissioner said.

Mr Enright said the only people aware of the searches about to be conducted were a small team in the ROC and the AFP.

Asked whether the ROC could have leaked to the media, Mr Enright said the ROC's media manager, who had only been in the role for two weeks, had told him he did not know anyone in the minister's office and had nor engaged with anyone in the minister's office.

Asked whether he believed the ROC had been politicised, Mr Bielecki said: "Not at all."

"This investigation is not into Mr Shorten - it is into the AWU."

The ROC currently has five investigations and one inquiry under way.

As well it is considering information from the Heydon royal commission and 18 whistleblower disclosures.